1. Field of the Invention
The present invention relates to a silicone resin composition, a luminous substance-containing wavelength-converting film, and a cured product thereof.
2. Description of the Related Art
In recent years, photonic devices of a blue light and a white light whose LED light-emitting wavelength is shorter have been developed and widely used. The resulting increase in the luminance of a light-emitting device, having such a shorter light-emitting wavelength, brings about a strong demand for a higher calorific value of the light-emitting device.
Silicone resins having a high transparency, heat resistance and light resistance have been focused on and widely used as a material for sealing and protecting such a high-luminance light-emitting device (Patent Document 1). Unfortunately, degradation of silicone resins remains technically problematic due to exposure of a high energy light and a high heat emitted from a light-emitting device.
In addition, commonly-used silicone resins are not provided with a sufficient gas barrier to sulfur-containing gases, resulting in such problems as the corrosion of conductive wires in LED light-emitting devices and silver materials used in optical reflective materials (Patent Documents 2 to 3). “Sulfur-containing gases” in the present invention mean gas compounds at normal temperature containing sulfur atoms in one molecule such as SOx and H2S. “Normal temperature” in the present invention is defined as an ambient temperature under a normal state, usually in the range of 15 to 30° C., preferably 25° C.
To solve the aforementioned problem, Japanese Patent No. 4671309 proposes a resin composition obtained by adding a reactant of a (meta)acryloyl group-containing silane coupling agent and an epoxy group-containing silane coupling agent to an addition-type silicone resin composition (Patent Document 4). Unfortunately, its insufficient moisture penetration resistance causes a defect in adhesiveness with a resin substrate such as polyphthalamide with time.